High discrimination ratio, broadband circularly polarized light photodetector using dielectric achiral nanostructures

oleh: Guanyu Zhang, Xiaying Lyu, Yulu Qin, Yaolong Li, Zipu Fan, Xianghan Meng, Yuqing Cheng, Zini Cao, Yixuan Xu, Dong Sun, Yunan Gao, Qihuang Gong, Guowei Lyu

Format: Article
Diterbitkan: Nature Publishing Group 2024-09-01

Deskripsi

Abstract The on-chip measurement of polarization states plays an increasingly crucial role in modern sensing and imaging applications. While high-performance monolithic linearly polarized photodetectors have been extensively studied, integrated circularly polarized light (CPL) photodetectors are still hindered by inadequate discrimination capability. This study presents a broadband CPL photodetector utilizing achiral all-dielectric nanostructures, achieving an impressive discrimination ratio of ~107 at a wavelength of 405 nm. Our device shows outstanding CPL discrimination capability across the visible band without requiring intensity calibration. It functions based on the CPL-dependent near-field modes within achiral structures: under left or right CPL illumination, distinct near-field modes are excited, resulting in asymmetric irradiation of the two electrodes and generating a photovoltage with directions determined by the chirality of the incident light field. The proposed design strategy facilitates ultra-compact CPL detection across diverse materials, structures, and spectral ranges, presenting a novel avenue for achieving high-performance monolithic CPL detection.